Large quantities of timber and packing materials are carried all over the world in ships and such goods remain largely useless at the point of arrival of the ship due to the likelihood of it containing pests, parasites, insects or other vermin from another country, such as for example borers, lice, ticks, fleas or termites. It is best that the timber dunnage and other bulk materials do not have to leave the confines of the wharf or port vicinity to travel to a distant site for effective treatment, since this would pose an environmental exposure risk.
Fumigation devices for bulk materials are known in the art that involve placement of a heavy, impervious blanket or other covering article over the materials followed by subsequent addition of toxic gas flow under the blanket to fumigate the covered goods. Current methods of fumigation under blankets are crude, ineffective at fully eliminating insect infestation since no mixing of gases with dunnage can occur, and highly dangerous from an occupational health standpoint since the gases used for effective fumigation are extremely toxic.
U.S. Pat. No. 5,318,789 relates generally to a method for fumigating produce and in particular fruit. U.S. Pat. No. 5,318,789 describes the specific construction of a vented container in which the fruit is packed in preparation for fumigation. The vented fruit containers are stacked in a purpose-built fumigation chamber of a fumigation facility and the fruit fumigated with a gaseous fumigant. The fruit containers are then transported out of the fumigation facility either to a cold storage area of a packing house or directly to shipment vehicles.